Hall effect sensors are used to detect and measure magnetic fields. Because electricity produces a magnetic field as it flows, Hall effect sensors can also be used to detect electrical currents. Motion or rates of rotation are sometimes measured using magnets positioned on a moving part with a Hall effect sensor positioned to detect the magnet as it moves past a fixed point. Hall effect sensors can also be used to determine the proximity of a known magnetic field, so certain distances can be measured. In operation, a current is induced across a Hall effect sensor plate, and that current is deflected when a magnetic flux passes through the plate. The stronger the magnetic flux, the more the current is deflected, and the deflected current produces a voltage difference across the sensor plate perpendicular to the induced current. The strength of the magnetic field passing through the plate can be determined by measuring the voltage across the sensor plate, where the voltage is measured perpendicular to the induced current.
Several design features influence the sensitivity of Hall effect sensors, including the length of the Hall effect sensor plate, the carrier concentration of the sensor plate, and the thickness of the sensor plate. Sensitivity is increased by producing a longer plate, a lower carrier concentration, and/or a thinner plate. Hall effect sensors are often incorporated into integrated circuits. Increasing the sensitivity of Hall effect sensors can produce integrated circuits that sense a magnetic field more reliably, because smaller magnetic fields can be detected. More sensitive Hall effect sensors can detect and measure smaller changes in magnetism, so more accurate measurements are possible.
Accordingly, it is desirable to develop integrated circuits having Hall effect sensors with thinner sensor plates and greater sensitivity, and methods of producing the same. In addition, it is desirable to develop methods for producing Hall effect sensors that do not increase the number of manufacturing steps to help control production costs. Furthermore, other desirable features and characteristics of the present embodiment will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.